成虎, 张存瑞, 邱开发, 王东升, 李宏男. 基于组合性能指标的立面差异化锈蚀桥墩时变抗震韧性研究[J]. 工程力学. DOI: 10.6052/j.issn.1000-4750.2022.05.0441
引用本文: 成虎, 张存瑞, 邱开发, 王东升, 李宏男. 基于组合性能指标的立面差异化锈蚀桥墩时变抗震韧性研究[J]. 工程力学. DOI: 10.6052/j.issn.1000-4750.2022.05.0441
CHENG Hu, ZHANG Cun-rui, QIU Kai-fa, WANG Dong-sheng, LI Hong-nan. STUDY ON TIME-DEPENDENT SEISMIC RESILIENCE OF BRIDGE PIERS CORRODED DISCREPANTLY ALONG HEIGHT UPON COMBINED CAPACITY INDEXES[J]. Engineering Mechanics. DOI: 10.6052/j.issn.1000-4750.2022.05.0441
Citation: CHENG Hu, ZHANG Cun-rui, QIU Kai-fa, WANG Dong-sheng, LI Hong-nan. STUDY ON TIME-DEPENDENT SEISMIC RESILIENCE OF BRIDGE PIERS CORRODED DISCREPANTLY ALONG HEIGHT UPON COMBINED CAPACITY INDEXES[J]. Engineering Mechanics. DOI: 10.6052/j.issn.1000-4750.2022.05.0441

基于组合性能指标的立面差异化锈蚀桥墩时变抗震韧性研究

STUDY ON TIME-DEPENDENT SEISMIC RESILIENCE OF BRIDGE PIERS CORRODED DISCREPANTLY ALONG HEIGHT UPON COMBINED CAPACITY INDEXES

  • 摘要: 为了研究立面差异化锈蚀桥墩在全寿命周期内的震后可恢复性能,该文基于结构震中响应和震后状态提出了一种“先判定损伤等级后评估可修复程度”的桥墩抗震韧性概率评价方法。以地震易损性分析为基础,基于最大位移角-残余位移角组合指标构建桥墩震后可恢复性曲线,给出桥墩各级破坏状态下多级可修复程度的概率计算方法。根据海洋环境的腐蚀特点,建立了立面差异化锈蚀桥墩的有限元模型,通过Pushover分析研究了全服役期内桥墩抗震性能的退化规律。采用增量动力分析(IDA)方法对不同服役年限的桥墩进行地震易损性分析,根据墩顶最大位移角定义桥墩破坏状态、以峰值加速度(PGA)表征地震动强度,从而建立起桥墩时变地震易损性曲线。以残余位移角为参考指标,对桥墩不同服役时间的各级破坏状态进行震后可修复程度的分类与统计,通过构建可恢复性曲线实现桥墩不同破坏状态下各级修复难度的概率评估。研究结果表明,随着服役时间的增长,钢筋锈蚀会导致桥墩抗震性能的不断退化。相比未锈蚀情况,桥墩服役100年后,承载力下降约20.22%,而侧向变形能力降幅可达75.30%。同时,随着服役时间的增长,桥墩各级破坏状态的地震失效概率逐渐增大,且震后修复难度也随之提高。当PGA为0.6 g时,桥墩从未锈蚀到服役100年,发生严重破坏的超越概率由16.92%上升到了35.66%,而震后需要简单修复的概率由14.17%上升至26.49%,并出现了较难修复和难以修复的情况。

     

    Abstract: To investigate the seismic resilience of bridge piers corroded discrepantly along height during their life-cycles, a probability-based evaluation method was proposed upon the seismic response and post-earthquake function state. The method was implemented by defining the damage states firstly, and then followed by dividing the repairable levels. Based on seismic fragility analysis, the recoverability curves of bridge piers were established according to the combination of the maximum drift (MD) ratio and the residual drift (RD) ratio, and the calculation process was presented for the probabilities of multistage repairable degrees of bridge piers at various damage states. The finite element model of non-uniform corroded bridge piers was established according to the erosion characteristics of the marine environment, and Pushover analysis was performed to study the degradation law of its seismic performance in the whole service period. The seismic fragility analysis was carried out using incremental dynamic analysis (IDA) method. The MD ratio was captured to define the damage state of bridge piers, and the peak ground acceleration (PGA) was adopted as the intensity measure of ground motions. Regression analysis was performed to establish the relationship between the MD ratio and the PGA, and seismic fragility curves were then obtained. Multistage repairable degrees of bridge piers were classified for each damage state, and the corresponding recoverability curves were obtained to assess the probability of every repairable degree. The results indicate that the corrosion of reinforcements causes the constant degradation of seismic performance of bridge piers when the service time increases. Compared with the non-corroded condition, when the bridge pier serves 100 years, the load bearing capacity and lateral deformation capacity decrease by 20.22% and 75.30%, respectively. Meanwhile, the increase of service time also enhances the exceedance probabilities of various damage states, and the difficulty of repair also increases accordingly. When the PGA is equal to 0.6 g, the exceedance probability of severe damage state increases from 16.92% to 35.66% after the bridge pier serves 100 years, and the probability of easy repair increases from 14.17% to 26.49%. In addition, the condition that the bridge pier is hard to repair appears.

     

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